NORTH AMERICAN DIPTKRA. 
355 
bristly on lower border, otherwise bare ; sides of face narrow, bare; facial ridges 
bristly for a short distance above vibrissae, which are decussate and inserted a 
little above oral margin at a constriction of the facial ridges; antennee very short 
inserted below middle of head, blackish or brown ; fii-st joint short, second much 
longer, bristly in front with a longer bristle before apex, third joint but little 
longer than second ; arista thickened for little less than half its length, with 
some microscoi'ic very short pubescence, black, 3-jointed, second joint not elon- 
gate; proboscis moderately stout, about as long as bight of head, black, brown 
at tij), labella well developed ; ])alpi rather slender, hardly thickened towai-d tip, 
blackish, with several black bristles on undersurface; occiput cinereous, black 
hairy, brownish-cinereous around the borders, with a fringe of black hairs on 
orbital margins. Thorax and scutellum cinereous, with three wide, brownish 
cinereous vittie terminating at scutellum ; thorax sparsely hairy, with very few 
bristles; scutellum with an apical, decussate pair of macrochtetse reaching be- 
yond base of second abdominal segment, two lateral ones on each side in front 
of the apical pair; humeri and pleune light cinereous. Abdomen conico-ovate in 
outline, first segment not shortened; color black, unevenly cinereous ])ollinose, 
black-hairy, with weak macrochfette only marginal; fir.st two segments each 
with a median pair of macrochsetaj and a lateral macrochseta-like bristle ; third 
segment with about ten, anal with about eight macrochfetfe. Legs black, femora 
slightly cinereous, long-hairy, middle and hind tibiae bristly; claws and pnlvilli 
elongate. IT'/wps a little longer than abdomen, narrow, without costal spine, 
grayish hyaline; apical cell opien, ending a little before tip of wing; fourth vein 
bent at an angle, with a well defined wrinkle at the bend ; hind cross-vein not 
straight, nearer to the bend of fourth vein ; tegulae grayish white, halteres 
flavous. 
9 . — Differs only in the considerably shorter claw’s and pnlvilli. The front is 
about the same width. Length 51 — mm. ; of wing 4 — 4S mm. 
Described from one % and three 9 specimens received from Mr. 
Cliarles Robertson, Carlinville, 111. Differs from Schiner’s description 
of }facronychia as follows : Tbe sides of face are narrow and bare ; the 
front is rather narrow, and of equal width in both sexes ; the arista 
is seen to be distinctly 3-jointed under a high-power lens. It belongs 
to Pachyophthahmis Br. and Bgst. as separated by them from Mucro- 
nyc.hia; and on account of still other differences beside those men- 
tioned above may perhaps better be located in the new genus. It 
has the front narrower than in Miltogramma. 
(lavicoriiis n. sp. % . — Black, cinereous and reddish. 
Eyes light brown, bare, facets larger in front; front a little over one-fourth width 
of head, rather prominent before, brassy or slightly golden, with some short, 
weak hairs outside the frontal bristles; face much wider than front; frontal 
vitta brownish, very narrow before, widening toward ocelli, where it divides into 
a prong on each side; face and cheeks silvery-white, facial dei)ressiou occupying 
one-half the width of face, sides of face, therefore, moderately wide, bare; frontal 
bri.stles de.scending only to base of antennae ; a pair of posteriorly directed bris- 
tles at each vertical angle, the outer shorter ones directed also outward ; next 
frontal bristle directed mostly backward, rest directed inward, decussate ; four 
